Eating melatonin-rich foods is linked to lower obesity and depression rates

A recent study published in the Journal of Human Nutrition and Dietetics suggests a link between dietary melatonin—obtained from everyday foods—and lower rates of obesity and depression. The research, conducted with a large cohort of Brazilian university graduates, found no such clear associations with other chronic diseases.

Understanding the Study

Researchers analyzed the melatonin content of 119 food items and examined its relationship to various health outcomes. This approach considered dietary melatonin not as a direct treatment, but as a potential marker of broader dietary patterns associated with health conditions. Prior research has indicated melatonin’s potential benefits for sleep, mood, and metabolic health.

How Dietary Melatonin Was Studied

The study utilized data from the Cohort of Universities of Minas Gerais (CUME+), an ongoing study focused on the impact of diet on noncommunicable diseases. Participants completed questionnaires detailing their sociodemographics, medical history, lifestyle, and dietary habits, including a food frequency questionnaire (FFQ). Dietary melatonin intake was estimated based on food composition data and adjusted for overall energy consumption.

Did You Know? Coffee, lentils and beans, and rice were identified as the primary dietary sources of melatonin in this study.

Key Health Outcomes Examined

The study focused on several health outcomes, including obesity (defined as a Body Mass Index or BMI of 30 kg/m² or higher), obstructive sleep apnea (OSA), hypertension, metabolic syndrome (MetS), type 2 diabetes (T2D), sleep duration, dyslipidemia, and depression. Diagnoses of depression and OSA were based on self-reporting.

What the Data Revealed

The analysis revealed no significant associations between dietary melatonin intake and OSA, hypertension, MetS, or T2D. While some associations with sleep duration and dyslipidemia were initially observed, they disappeared after accounting for age and sex. However, a clear inverse relationship emerged between dietary melatonin intake and both obesity and depression.

Expert Insight: The finding that intermediate levels of melatonin intake—between 14,900 to 34,400 ng daily for obesity and 14,900 to 25,000 ng daily for depression—showed the strongest associations suggests a nuanced relationship. It’s possible that the body responds optimally to a certain range of melatonin intake from food sources, rather than simply benefiting from higher and higher amounts.

Specifically, individuals consuming between 14,900 and 34,400 ng of melatonin daily were less likely to be obese, and those consuming between 14,900 and 25,000 ng daily were less likely to experience depression.

What Might Happen Next

Given these findings, further research could explore the mechanisms by which dietary melatonin might influence metabolic and neurobehavioral health, potentially through anti-inflammatory pathways. Longitudinal studies—following participants over time—could help determine whether increasing dietary melatonin intake actually *prevents* obesity and depression, or if people who are already at lower risk for these conditions simply tend to consume more melatonin-rich foods. It is also possible that future studies will investigate optimal dietary melatonin levels for different populations and health conditions.

Frequently Asked Questions

What was the average daily melatonin intake of participants?

The average daily melatonin intake among the 8,320 participants was 25,554.7 ng, with males consuming significantly more than females.

Were there any dietary patterns associated with higher melatonin intake?

Higher melatonin intake was associated with lower consumption of protein, cholesterol, saturated fats, and monounsaturated fats, and higher intake of fiber and carbohydrates.

What type of study was conducted?

This was a cross-sectional study, meaning data was collected at a single point in time. Therefore, the study cannot prove cause and effect, only associations.

Could incorporating more melatonin-rich foods into your diet be a simple step toward supporting overall well-being?